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(No Model.) 5 Sh eets-Sheet 1. J. J. ABELL & O. B. GIFPORD. PENDULUM FOR ELECTRIC CLOCKS.

Patented Oct. 19, 1886'.

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(No Model.)

5.Sheets--Shet 2. J. J. ABELL & O. B. GIPFORD. PENDULUM FOR ELECTRIC CLOG Pat No. 351.239. y en Oct. 19, 1886. I I v (NdModeL) 5 SheetsSheet 3. J. J. ABELL 8a 0.13- GIFPORD.

PENDULUM FOR ELECTRIC CLOCKS. No. 351,239.

Patented Oct. 19, 1886.

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(No Model.) I 5 Sheets-Sheet 4. J. J. ABELL & C. B. GIFFORD.

PENDULUM FOR ELECTRIC CLOCKS. No. 351,239.

Patented Oct. 19, 1886.

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(No Model.)

5'Sh66ts-Sheet 5. J. J. ABELL & O. B. GIFFORD. PENDULUM FOR ELECTRIC CLOCKS. .No. 351,239.

Patented Oct. 19. 1886.

q vi lihaoow UNITED STATES PATENT OFFICE.

JOHN JAMES ABELL AND CLARENCE BEN GIFFORD, OF COLESBURG, KY.

SPECIFICATION forming part of Letters Patent No. 351,239, dated Qctober 19, 1886.

Application filed August 4, 1886. Serial No. 210,009. (No model.)

To aZZ whom it may concern:

Be it known that we, J only J AMES ABELL and CLARENCE BEN Grrronn, citizens of the United States, residing at Colesburg, in the county of Hardin and State of Kentucky, have invented a new and useful Improvement in Pendulums for Electric Clocks and Means for Oscillating the Same, of which the following is a specification.

Our invention relates to an improvement in pendulums for electric clocks and means for oscillating the same; and the object of our invention is to provide a mechanism for oscillating the pendulum of an electric clock or system of electric clocks.

A further object of our invention is to provide a compensating mechanism for the pendulum, to prevent variations in temperature from affecting the accuracy of the time mechanism; and a further object of our invention is to provide a regulator for the pendulum, by means of which the latter may be adjusted.

To these ends our invention consists in the peculiar construction and combination of devices, that will be more fully set forth. hereinafter, and particularly pointed out in the claims.

In the drawings, Figure 1 is a front elevation of an apparatus embodying our improvements. Fig. 2 is a side elevation of the same. Fig. 3 is a top plan View, portions of the supporting plate being broken away so as to disclose subjacent mechanism. Fig. 4 is a bottom plan view. Figs. 5, 6, and 7 are detailed views. Fig. 8 is a diagram in which the circuits are traced.

Arcpresents the case in which the mechanism is inclosed. In the upper portion of this case are secured brackets B, which support a horizontal metallic plate, 0. side of the plate is secured a horseshoe elec tro-magnet, D, by'means of a threaded stem, E, which depends from the plate and passes between the coils, and a yoke which bears under the coils, and through which the stem passes, the said yoke being clamped under the coils by a thumbnut, T, which works on the lower threaded end of the stem.

G represents a bracket which depends from the lower side of the plate, and has at its lower end a horizontal outwardly-extending arm, 9.

On the lower Vertical bearing-screws II extend through the plate and through the arm 9, with their points toward each other, the said screws being in a line with each other.

I represents an armature having at its inner end a pivot-arm, t, the ends of which are pointed and have their hearings in depressions or recesses made in the points of the setscrews H1 The armature is in proximity to the poles of the electro-magnet, and its vibrations are limited by the adjusting-screws K, which approach on opposite sides and pass through the vertical arms of a yoke, L, that depends from the outer side of the plate 0.

The outer end of the armature I, which projects beyond the front edge of the plate, has a right-angled horizontal arm, M. A hard-rubher or other suitable non-conducting plate, M, depends from the arm M. To one side of the said plate is attached a vertical plate or strip, N, made of conducting metal, and to the op posite side of the plate M is attached a similar plateor strip, 0, which is also made of conducting metal. The lower end of the conducting-plate N has a contact-point, N, made of platinum wire, and the plate 0 has a similar contact-point, O, the said points N and 0 extending toward each other. A conductingwire coil, N connects the plate N with a binding-post, 1?, that is attached to the plate 0, and insulated therefrom, and a conductingwire coil, 0 connects the plate 0 with a binding-post, R, that is also attached to the plate 0, and is insulated therefrom. From the lower side of the plate 0 depends a stud, S, forming the bearing for a thumbscrew or drum, S, to which is attached one end of a coiled tension-spring, S the other end of the said spring being attached to the armature.

T represents a supporting arm which eX- tends outwardly from the front side of the plate G. The outer end of this arm is recessed or cut away on one side, and in the said cutaway portion is placed aj aw, T, which is secured to the arm by a screw, T From a dowel-pin, T, which enters an opening in the opposing face of the arm T.

V represents an arm which projects from the front side of the plate and'rests against one side of the arm T. This arm V has at its one side of the outer end of the jaw Tprojects IOO outer end a right-angled extension or arm, V, which extends across the outer end of arm T, ata suitable distance therefrom.

XV represents a vibrating arm or crutchwire, having its upper end pivoted between the inner side of the arm V and the front end of the arm T, directly in line with the center of the latter and with the center of the plate 0. The lower end of the vibrating arm hasa fork or yoke, TV, which extends rearwardly. This arm V has near its upper end a contact spring, XV", made of thin sheet-steel, and provided at its upper end with a ioi'wardly-extending arm of platinum wire, -W, forming a contact-point, which extends outwardly between the contact-points N and O. lVhen the vibrating arm is in an exactly vertical position, the point W is out of contact with both the points N and O.

X represents a flat springleaf, which has its upper portion secured between the arm T and its jaw T, so that the leaf is prevented from vibrating laterally, but is free to be adjusted up and down. The upper end of the leaf is pivoted in the bifurcated lower end of an adj USiJlllg-SCIOW, X, and the lower end of the leaf has a block, X in which is made a forwardly and upwardly extending open slot, X. The upper end of the spring-leaf is pivoted to the lower end of the adj Listing-screw, in order to permit it to swing slightlybaek or forth with the pendulum in the event that the clockcase is not in a perfectly vertical position. The lower portion of the screw X, which ex.- tends below a lever, to be hereinafter described, is provided with a scale, the degrees of which correspond with the pitch of the screw-threads.

Y represents a slotted link, that has its lower end pivoted to a stud, which p rqjects from the upper side of the plate 0, at the center and rear side of the latter. v

From the lower side of the plate 0 depends a pair of iron rods, (1, connected at theirlower ends by a horizontal bar, 7), the said rods and bar forming a stirrup.

0 represents a brass rod, which has i tslowcr end stepped in a central recess made in the upper side of the bar I). The upper portion of the brass rod 0 passes through an opening in the center of the plate 0, and the extreme upper end of the said rod 0 is bifurcated.

(7. represents a. supporting-lever of the third class, which has its rear end secured in the slotted link Y. At the center of the lever are trunnions c, which bear in semicircular recesses in the upper bifurcated ends of the brass rod, whereby the said lever has its center fulcrumed on the upper end of the brass rod. The outer or front end of the lever has a head, f, provided with a vertical opening, 71, to receive the unthrcaded portion of the screw X. An annular nut, 71:, which is graduated into ten numbered spaces, each of which is subdivided into tenths, works on the upper threaded portion of the screw X, and bears upon the upper end of the lever (I. At the front end of the latter is a pointer, Z.

"in represents the pendulum-rod, which iS made of iron and has its upper end provided with an open vertical slot, through which extends a transverse pin, n. The pendulunr bob 0 is firm] y secured to the lower end of the red by a screw, 1). The pendulum-rod is attached to the lower end of the springleaf by inserting the block X of the latter in the slot at the upper end of the pendulum-rod, and causing the pin a of the rod to engage the slot in the block. The fork or yoke of the vibrating armengages the )endnluin-rod, so that the pendulum and the vibrating ar'm are caused to oscillate together.

The plate 0 is provided on its lower side with an insulated binding-post, 1', which is connected to one terminal of the coils of the electromagnet, and with a similar insulated binding-post, s, which is connected to the opposite terminal. of the coils of the clectro-inagnet. A binding-post, if, is on the upper side of the plate 0, and is connected electrically therewith. In order to insure electric connection between the vibrating arm and the plate 0, we connect the upper end of the vibrating arm wit-h the arm V by a conducting-wire coil, U.

On the lower side of the inclosing case is a compartment in which is located a galvanic battery, which usually consists of only one cell. The compartment is large enough to receive two cells. On one side of the case is an insulated conducting-wire, '0, having its upper end connected to the bindingpost i, and its lower end connected to one pole of the battery. The lower end of the wire a has a free branch or terminal, 0. In the opposite side of the inclosing-case is another conductingwire, it, the upper end of which is connected to the binding-post son the upper side of the plate 0, and the lower end is connected to the remaining pole of the battery. From the lower end of the wire '20 extends a free branch or terminal wire, in. The wires 1; and iv, the plate 0, and the arm V form the local circuit. hen the battery needs replenishing, a new one is connected to the terminal wires w and 1: before the one in use is removed, and thus the electric current is not interrupted. In the top of the case are two binding-posts, a; and y. A conducting-wire, :0, leads from the post .v to the binding-post It, and a conducting-wire, y, leads from the post 9 to the post 5. The line-wires a are attached to the posts a; and y, and form alinecircuit in which is included the electro-1nagnet of an electric clock, .2, or a system of such clocks, which is not more particularly described, as it may be of the ordinary form, and forms no part of this present invention.

The vibrating arm forms av switch.

The operation of our invention is as follows: 'hen the pendulum at rest, the point X is out of contact with both the points J and O, and consequently both the local and the line circuits are broken. In order to start the apparatus the pendulum is swung to the left, so

as to cause the point W to contact with the point N, thus closing the local circuit, and causing the current from the battery to pass through. the coils of the electro-magnet D, and thus magnetize the cores thereof and cause them to attract the armature. This movement of the armature causes the point N to bear upon the point VV at the free end of the spring 'W with sufficient power to impart a slight impulse to the pendulum when it reaches the limit of its movement to the left, and it then swings to the right, causing the local circuit to be broken by breaking contact between the points N and W, thus instantly demagnetizing the electro-magnet D, and the tension-spring then moves the armature to the left while the pendulum is swinging to the right, and causes the points 0 and W to contact, thus establishing the line-circuit, and causiu g acurrent to traverse the linewires to the electro-magnets in the clock or system of clocks in the circuit, to actuate the same. The pendulum is thus impelled in one direction by the attraction of the electromagnet on the armature, and in the opposite direction while the loealcircuit is broken by the action of the tension-spring.

From the foregoing description it will be readily understood that we employ only one battery to operate both the local and the line circuits.

The iron rods which depend from the plate 0 and carry the cross-bar forming the stirrup, and the brass rod, which has its lower end stepped in. the stirrup and its upper end attached to the lever from which the pendulum is suspended, form a compensating or automatic regulating apparatus, to counteract the efthcts of contraction and expansion of the pendulum-rod under variations of tempera ture. If the pendulum-rod be heated a cer t-ain number of degrees, it will expand a certain distance, and the iron rods will also expand at the same time and in the same direction. 1 The brass rod, which expands farther under the sam c temperatiu'e than the iron rods, moves upwardly against the suspending leverarm and raises the center of the same through a space equal to the excess of the expansion of the brass rod over the expansion of the iron rods and. the lever-arm, and consequently the pendulum, which is SUSPOHClOCl from. the outer extremity of the lever, will be raised through a space equal to twice this excess. If, then, the length of the brass rod be such that its excess of expansion is one-half the expansion of the pendulum-rod, including the leaf X, this brass rod will automatically raise or lower the pendulum just much as the pendulum-rod and leaf may expand or contract under theinfiuencc of heat or cold.

To determine accurately the length of brass rod necessary to compensate a pendulum of any given length. the following formula is used: 1 LXi '2 b-@ where B is the required length of brass rod.

, or B: 0.924 L, approximately,

L is the length of pendulum-rod and leaf to be compensated. i is coefficient of the expansion of iron, (approximately 0.0000122.) b is coefficient of the expansion of brass, (approxi mately 0.0000188.)

The function of the screw :10 and the graduated nut is to adjust the pendulum-rod to the exactly correct length, so that the apparatus will keep correct time. As the nut is divided into ten spaces, each of which is subdivided into ten degrees, it will be seen that a very hue and accurate adjustment of the pendulum may be readily obtained.

Having thus described our invention, we cla-i1n- 1. The combination of the local circuit, including the battery, the clectro-magnet, the armature having the contact-points, and the vibrating arm having the contact-spring between the contaet-points and connected to the pendulum, and. the line-circuit, including the electric clock or series of electric clocks, whereby when the pendulum swings in one direction the current from the battery flows through the local circuit, and when the pendulum swings in the contrary direction the current from the battery flows through the linecircuit, for the purposes set forth, substantially as described.

2; The combination, with the main circuit, including the electric clock, and local circuit, including the electro-magnet I), of the armature having the contact-points connected with the main and local circuits, and the vibrating arm included in one circuit and playing be tween the contact-points of the armature, to automatically make and break the main and local circuits alternately, for the purpose set forth, substantially as described.

3. The combination of the pendulum, the vibrating arm connected to the pendulum, the armature adapted to strike opposite sides of the vibrating arm to swing it and the pendulum, and the electro-magnet to attract the armature, substantially as described.

4. The combination of the pendulum, the

vibrating arm connected thereto and havingthe spring V, the armature havingthe arms or steps to strike opposite sides of the said spring alternately, and the electro-magnet to attract the armature, substantially as de scribed.

5. The combination of the vertical. iron rods having the crossbar at their lower ends, the brass rod supported on the crossbar, the fulcrnmed lever bearing on the brass rod, and the pendulum suspended from the said lever, substantially as described.

6. The combination of the plate O, the iron stirrup depending therefrom, the brass rod supported on the said stirrup, the lever connected to the brass rod and movable thereby, the screw as in the said lever, the nut thereon, and the pendulum suspended from the screw, substantially as described.

7. The combination of the plate 0, the iron stirrup depending therefrom, the brass rod supported on the said stirrup, the lever e0n- :v, the leaf pivoted to the lower end thereof 15 nected to the brass rod and movable thereby, and suspended therefrom, the pendulum susthe screw a", in the said lever, the graduated pended from the leaf, and the clamp to prennt thereon, and the pendulum suspended vent lateral vibration of the leaf, substantially 5 from the said screw, substantially as deas described.

scribed; In testimony that we claim the foregoing as 20 S. The combination of the supporting-screw our own we have hereto ail'ixed our signatures .r with the spring-leaf suspended from the in presence of two witnesses. .screw and having the head provided with JOHN JAMES ABELL 1o 1ncl1ned open slot, and the pendulum havlng CI XPFYGE BE GIFFOPD the slot at the upper end of its rod to receive N x the head, and the transverse pin to enter the Witnesses: open slot therein, substantially as described. JOHN H. TELLS,

9. The combination of the supporting-screw Y J. XV. MATTHIs. 

